Are you aware that loss is not inherently stressful? It only becomes so by being afraid of expressing the emotion ie crying or expressing it in some other way. The problem is the majority of children are taught to be afraid of expressing sadness rather than being directed to express it in a clearer and more appropriate way by talking and saying what is upsetting them.
A baby cries, it is one of the few ways a baby has of communicating when it needs something. At the age of around 4, children can talk but they still break into tears every few minutes and this is where parents almost always get this wrong. They do not direct the child to a more appropriate way of expressing the sadness, by moving them to expressing the emotion by talking. Instead parents get angry with the child and tells it to shut up, stop crying etc They show disapproval and the child becomes afraid of expressing their sadness. This is where the stress comes from! Sadness and loss should not be stressful, it is not meant to be. However parents get it so wrong bringing up their children by making this common mistake that virtually everyone experiences unnecessary stress when they lose something.
Chances are that this intense stress, because you could not express your sadness, damaged your kidney energy in TCM terms. This can affect the mood and causes chronically high cortisol levels because the body adapts to the stress and goes into survival mode. This can show in the iris of the eye just inside 6 o clock in both irises. It usually shows as a grey marking like a segment of a cake and works inwards from the iris edge towards the nerve wreath which is approximately a third the way from the pupil. Just inside this ring are the adrenal glands BTW. https://cdn.naturalhealthcourses.com/wp-content/uploads/2015/10/SNHS-iridology-6.jpg
For people who are also afraid of expressing anger, there is a double wammy of stress which can cause Depression and for some that can cause fatigue, tiredness, infections, skin problems among other things.
The diarrhoea might of been caused by clostridium difficile infection which is fairly common with Antibiotics .